Abstract

We investigate the dynamics of amplified spontaneous emission(ASE) in self-assembled InAs/GaAs quantum dots, using pulsed optical excitation of an edge-emitting sample at room temperature. A material gain of is determined for 800 nm excitation with pulses. Using photoluminescence up-conversion, we show that increases in both electron–hole pair density and photon density in the excited stripe cause a significant decrease in the decay time from 2.2 ns, corresponding to spontaneous emission, to about 0.9 ns, corresponding to stimulated emission or ASE. A carrier capture time of 10 ps limits the onset of the ASE process for short stripe lengths.